For systems containing sensitive instrumentation, it is typically desirable to minimize vibration such that the instrumentation may perform at an optimal level while avoiding damage to the instrumentation. For example, in tactical weapons such as airborne lasers mounted on aircraft, a beam director is typically included for controlling the direction along which a laser beam is projected to a target. The beam director may include a turret assembly to allow for directional control of the laser beam within a universal range of motion.
In order to maximize the effectiveness of the laser beam, it is desirable to control the direction along which the laser beam is projected with a high degree of precision. As part of its directional control system, the beam director may include sensitive optical systems and electronic components mounted within the turret assembly and which may facilitate target acquisition and directional control of the projected laser beam. In order to maximize the precision with which the beam is projected onto the target, it is typically desirable to minimize vibration of the turret assembly.
Although the turret assembly may be mounted at any location on the aircraft, tactical lasers may be mounted at locations subject to air turbulence. For example, certain tactical lasers may be mounted on an underside of a fuselage of the aircraft. Such mounting is distinct to other mounting locations wherein the beam director may be housed within a turret positioned on the nose of the aircraft. Although mounting on the underside of the fuselage provides certain operational advantages, such location exposes the turret assembly to undesirable aerodynamic effects. For example, significant aerodynamic turbulence may be present in the fuselage area where the turret assembly is mounted due to interactions between the air flow and the turret assembly and aircraft. Such aerodynamic turbulence is manifested as pressure fluctuations that may be non-uniformly and/or non-synchronously imposed on the turret assembly. Additionally, the turret assembly may produce additional aerodynamic turbulence and pressure fluctuations due to flow separation aft of the turret assembly as well as due to specific configuration features of the turret assembly that create local flow separation.
Unfortunately, such non-uniform loading on the turret assembly induces vibration which is transmitted to sensitive electronics and optics contained within the turret assembly. Such vibrations affect the performance of the optics and electronics and thereby affects the precision with which the laser may be projected to a target. In this regard, vibrations induced by aerodynamic loading on an outer surface of the turret assembly and which are transmitted to the beam director result in jittering of the laser beam which, when projected onto a target, minimizes the energy density with which the laser may be applied to the target.
Prior art attempts to reduce aerodynamically-induced vibration have taken several approaches. In one approach known as the turret-in-turret approach, an outer turret is mounted to the aircraft. An inner turret is mounted to the optical system and moves synchronously with the outer turret without physical contact to the outer turret. The inner turret has a platform for mounting sensitive instrumentation. The platform is vibration-isolated such that direct transmission of aerodynamically-induced vibration from the outer turret is minimized or prevented. Unfortunately, the turret-in-turret approach requires duel-nested deployment mechanisms with isolated load paths to prevent the transmission of vibration to the instrumentation. Because of the duel-nested deployment mechanisms, the turret-in-turret approach is relatively complex and results in a configuration that is relatively high in weight, cost and volume, and requiring a high degree of maintenance.
As can be seen, there exists a need in the art for a vibration isolation assembly for an aerodynamic object such as a turret assembly of a beam director which minimizes the transmission of aerodynamically-induced vibration to sensitive optics and/or electronic components. Furthermore, there exists a need in the art for a vibration isolation assembly for an aerodynamic object which is simple in construction, light in weight and low in cost as a means for reducing or eliminating mechanical vibration.